function f_submit() {
    let uname = document.getElementById("username");
    let pwd = document.getElementById("password");


    pwd.value = md5(pwd.value);

    if(uname.value === "admin"){
        if(pwd.value === md5("000000")) {
            return true;
        }else{
            alert("密码错误");
        }
    }else {
        alert("用户名错误");
    }
    return false;

}